Science > Meetings > 2024 > 243rd American Astronomical Society Meeting > ALMA Special Session AAS 243

ALMA Special Session AAS 243

243rd American Astronomical Meeting - New Orleans Convention Center | New Orleans, Louisiana | January 7-11, 2024


ALMA as a high-z powerhouse: the impact of the Wideband Sensitivity Upgrade


The NAASC will host a special session at the upcoming Winter AAS Meeting in New Orleans, held on Monday January 8, 2024, 10am to 11:30am (Central Time). This special session will present high-profile results obtained through ALMA programs in different areas of high-z studies – including large programs, current and expected synergies with high-sensitivity facilities, and the expected yield from ALMA observations after different phases of the Wideband Sensitivity Upgrade (WSU)are achieved. The session will include 4 invited talks by J. Yang (U. Arizona), A. Long (UT Austin), J. Spilker (Texas A&M) and D. Burgarella (LAM Marseille), and a short general presentation of the WSU.


In recent years, the use of ALMA for the characterization of high-z sources (galaxies, AGNs and quasars) has considerably expanded beyond the initial goal to detect molecular emission in Milky Way analogs at z = 3. ALMA will soon acquire a new and transformational role in the field with the implementation of the ongoing Wideband Sensitivity Upgrade (WSU), which will upgrade ALMA’s digital path, correlator, and the first three wideband receivers by the end of this decade, with additional receiver bands to follow. The current impact of ALMA is demonstrated by an increasing number of high-profile publications on sources at z 2~9 on questions as diverse as AGN jets kinematics, lensed dusty galaxy surveys, molecular composition of the cold gas component of SFGs, and the establishment of precise spectroscopic redshifts using atomic and ionized lines of C and O. The recent installation of the new ALMA Band 1 (35-50 GHz) also opened the ability to search for redshifted low-J CO lines, which are a good diagnostic for estimating the mass of the molecular gas reservoir. Considering the significant discovery space in this domain to be opened by current and future facilities – JWST and Roman in particular - ALMA will leverage the expected trove of high-z detections by providing for a significant number of these sources the baseline physical context to understand AGN accretion and galaxy evolution across cosmic times. The WSU, in addition to allowing much more efficient spectral scanning for redshift surveys, will provide dramatically improved sensitivity across the board (line sensitivity by a factor ~1.5, continuum sensitivity by a factor ~1.6-2) directly translating into deeper and more efficient detections.